Search results for " Zinc"

Nanocompositi a base di polistirene e ossido di zinco: azione disperdente delle molecole POSS

2014

Effect of the Si doping on the properties of AZO/SiC/Si heterojunctions grown by low temperature pulsed laser deposition

2020

Abstract The structural and photoelectrical properties of Al-doped ZnO (AZO)/SiC/p-Si and AZO/SiC/n-Si heterojunctions, fabricated at low temperature by pulsed laser deposition, were investigated by means of a number of techniques. Raman analysis indicates that SiC layers have the cubic 3C-SiC phase, whilst X-ray diffraction measurements show that AZO films exhibit a hexagonal wurtzite structure, highly textured along the c-axis, with average crystallites size of 35.1 nm and lattice parameter c of 0.518 nm. The homogeneous and dense surface morphology observed by scanning electron microscopy was confirmed by atomic force microscopy images. Moreover, UV–Vis-NIR spectra indicated a high trans…

Characterization of a CZT focal plane small prototype for hard X-ray telescope

2005

The promise of good energy and spatial resolution coupled with high efficiency and room temperature operation has fuelled a large international effort to develop cadmium zinc telluride (CZT) for hard X-ray applications. We are involved on the development of a hard X-ray telescope based on multilayer optics and focal plane detector operative in the 10-80 keV energy range. This telescope requires a high efficiency focal plane providing both fine spatial resolution and spectroscopy with a compact and robust design. This paper reports preliminary results on the characterization both in spectroscopic and spatial response of two small pixellated CZT detectors (10times10times1 mm3 and 10times10tim…

Statistical Approximation of Fourier Transform-IR Spectroscopy Data for Zinc White Pigment from Twentieth-Century Russian Paintings

2017

We present a statistical model for approximation of experimental Fourier transform-IR spectroscopy (FTIR) data for paint samples from paintings of different ages. The model utilizes random variations in some parameters (initial ageing rate, degree of change in ageing rate and time at which the change occurs). We determine the parameters characterizing variation in the paint composition and the storage conditions for the paintings. The numerical calculation is qualitatively consistent with the experimental data. In the proposed model, changes in the initial composition of the paint and the storage conditions make about the same contribution to the experimentally observed scatter in the data …

Experimental investigation on the efficiency of zinc(II) recovery from waste streams by TBP liquid-liquid extraction

2016

In many industrial processes the presence of zinc in the wastewater may represent an obstacle to its high efficient regeneration. This is the case of the treatment of spent pickling solutions aiming the recovery of hydrochloric acid via pyrohydrolysis techniques. Hydrochloric spent pickling solutions from steel processing contain relevant amount of metals such as iron (Fe) and zinc (Zn) that may significantly affect recovery of hydrochloric acid (HCl) through pyrohydrolysis. In fact, although Fe may be recovered as ferric oxide (Fe2O3) and does not have a substantial effect on pyrohydrolysis process, zinc chloride (ZnCl2) evaporating can occlude nozzles and stick to the pyrohydrolysis react…

Recovering of zinc(II) from spent pickling solutions by liquid-liquid extraction

2015

Hydrochloric acid can be successfully recovered from spent pickling liquors with high efficiencies via pyrohydrolysis techniques. In the pickling solution feed, other metallic ions are typically present besides iron (mainly Fe2+) such as zinc(II). In order to avoid undesirable effects, zinc(II) has to be removed, because zinc chloride evaporates and sticks to the reactor walls, as well as it contaminates iron oxides product1. Moreover, zinc recovery is economically affordable because it allows the marketing of some products such as ZnCl2 and ZnSO4. In the present work, liquid-liquid extraction process has been selected to recover zinc(II) from pickling liquors, using suitable extractant age…

Creixement cristal·lí mitjançant la tècnica MOCVD i caracterització morfològica i estructural dels òxids de cadmi i zinc

2019

L'òxid de cadmi (CdO) i l'òxid de zinc (ZnO) han estat postulats com dos materials amb gran potencialitat en un ampli ventall d'aplicacions tecnològiques. Pel que fa a les seues propietats físiques, ambdós presenten un caràcter semiconductor de tipus “n”, sense dopatge intencionat. A més, el seu bandgap directe a 2.2 i 3.3 eV, respectivament, asseguren un bon grau de transparència òptica en la regió infraroja i visible de l'espectre electromagnètic. La projecció d'aquests compostos en camps com la plasmònica o les tecnologies basades en transicions intersubbanda fa convenient el control per a l'obtenció de capes molt primes. Malgrat això, gairebé tots els treballs publicats reporten capes p…